Display screen or portion thereof with a graphical interface



FIG. 1 is a front view of a first embodiment of a display screen or portion thereof with a graphical interface showing my new design;

FIG. 2 is a front view of a second embodiment of a display screen or portion thereof with a graphical interface showing my new design; and,

FIG. 3 is a front view of a third embodiment of a display screen or portion thereof with a graphical interface showing my new design.

The dashed lines, broken text, and broken graphics illustrate portions of the display screen or portion thereof with a graphical interface that form no part of the claimed design. 

CLAIM I claim the ornamental design for a display screen or portion thereof with a graphical interface, as shown and described. 